Solvent treating



1940- G. w. GURD ETAL 2,225,910

SOLVENT TREATING Filed Jan. 25, 1940 RAFFINA TE .ssrnna-rozz,

COOLER SOLVENT 2ECOVZY UlV/T i %,4 l 7 new Patented Dec. 24, 1940 UNITED s'r-Arss ammo socvmvr rename George W. Gard,

Walter on to Standard Oil ontariacanadgand Sarnia, N. Munster, Port Huron. lliela. align- Development Company, a

corporation of Delaware Application January 25, 1940, Serial No. new

8 Claim.

This invention relates to the treatment 01 mineral oils with selective solvents. The invention is particularly concerned with the treatment of mineral oils imder conditions to segregate the 5 relatively more aromatic constituents from the relatively more paramnic constituents by utilizing a solvent selected from the class of alkyl aryl sulionamides. It is known in the art to treat mineral oils with various selective solvents which have the ability to segregate the relatively more aromatic constituents from the relatively more parafllnic constituents. Solvents usually employed are selected irom the class of substances which have a preferential selectivity for the relatively more aromatic type compounds, as for example, phenol, iurfural, sulfur dioxide, cresol, nitro benzene, aniline, beta beta dichlor diethyl ether, and the like. Mixtures of these solvents may be emplayed, as well as other substances such as liqueiied normally gaseous hydrocarbons, in combination with the above described class of solvents. The oil and solvent are contacted by various means, as for example, by batch or semi-batch processes. However, the usual method of treating the oil is to contact the oil and solvent in a counter-current solvent treating tower process. in this operation, the heavier phase, usually the solvent, is introduced at the top of a countercurrent treating tower while the lighter phase, usually the oil, is introduced at the bottom or center section of the countercurrent treating tower. Efllcient contact between the countercurrently flowing phases is secured by various and rafllnate phase by suitable means, usually by distillation.

We have now discovered a class of solvents which are particularly desirable and eifective ior segregating mineral oils into their relatively more parafllnic and into their relatively more aromatic fractions. The solvents of our invention are also distributing and contacting means such as coneflective tor the segregation of relatively more unsaturated fractions from the relatively more saturated fractions. 'lhe solvents of our inventlon are selected from the class of alkyl aryl suiionamldes. which substances may be represented by the following structural formula;

1 B-N o ai o in which R. represents an alkyl group and R1 represents an aromatic ring.

The process of our invention may be readily understood by reference to the attached drawing illustrating one modification oi the same. A feed oil, which tor the purposes oi description is taken to be a cracked naphtha boiling in the motor iuel boiling range, is introduced into countel-current treating tower i by means of feed line 2. The oil flows upwardly through tower I and contacts downflowing solvent which is introduced into the tower by means of solvent feed line 3. For purposes of description the solvent Temperature and pressure conditions are adapted to secure the formation of a ramnate phase and a solvent extract phase. The raflinate phase is removed from tower I b y means of line 4 and introduced into solvent recovery unit 5. The solvent is removed from solvent recovery unit 5 by means of line 6, while the solvent-tree rafllnate is removed by means of line 1. If desired, the rafiinate phase may be cooled by means of cooler 3 and passed into raflinate separator l. The precipitated phase may be withdrawn from solvent separator 9 by means of line I. and handled in any manner suitable. Under certain conditions it may be desirable to return at least a portion of the precipitated phase to the counter-current treating tower by means of line H. The solvent extract phase is withdrawn from tower i by means of line i! and passed to solvent recovery unit 83. The solvent is removed from unit 13 by means of line it, while the solvent-free extract is removed by means of line it. The-solvent means of line is.

and at normal or elevated pressures.

extract phase also may be cooled in cooler It and passedto solvent extract separator l1. The precipitated phase may be withdrawn from solvent separator I I by means of line it and treated in a suitable manner. Under certain conditions it may be desirable to return at least a portion of the precipitated phase to tower l by The selectivity and solvent power of the selective solvent may be modified to any extent'by maintaining a temperature gradient in the tower or by introducing solvent modifying agents at a plurality of stages by means of lines 20, 2|, 2!, and 23.

The process of the present invention may be widely varied. The solvents are selected from the class of alkyl aryl sulfonamides. Suitable solvents of this class are, for example, phenyl ethyl sulfonamide, monoand di-hydroxy phenol propyl sulfonamide, propyl benzene butyl sulfonfollowing examples are given which should not be construed as limiting the invention in any manner whatsoever:

Example 1 tion:

Initial boiling point 192 F. 50% distilled ,215" F. Final boiling point 274 F.

The following results were secured:

ma Raflinate Extract F Below 0 F. 1.4261 at 0.. 1.4612 at 20 C Percent aromatics 83% 26 66. Yield 32 18.

Example 2 amide, butyl benzene propyl sulfonamide, and the like. Especially desirable solvents are the toluene alkyl sulfonamides, as for example, toluene methyl sulfonamide, toluene propyl suli'onamide, toluene butyl sulfonamide, and toluene The effectiveness of the solvents of the present invention may be readily seen by the following results secured by treating various portions of an hexyl sulfonamide. Preferred toluene alkyl sulidentical feed stock with various solvents:

"assets" 'ii33l Methylene Feed Raff. Ext. Feed am. Ext. Feed Ralf. Ext.

Gravity 54.8 55.4 43.2 54.3 50.5 41.5 54.3 55.2 45.2 Refraotiveindex--.' 1.4249 1.4196 1.4558 1.4249 1.4192 1.4433 1.4240 1.4200 1.4500 Percent aromatics. 18.8 60.0 25.0 18.6 45.0 25.0 19.5 53.5 Yiel 85.0 15.0 75. 5 23. 5 83.8 15. 2

fonamide solvents are those in which the alkyl group contains from one to four carbon atoms in the molecule. An especially desirable solvent is a mixture of ortho and para toluene ethyl sulionamides.

The operating conditions may be widely varied and the extraction operation may be carried out at temperatures in the range from 50 to 300 F. In general, when treating oils boiling in the motor fuel boiling range with ortho and para toluene ethyl sulfonamide,-it is preferred that the temperature be in the range from about 60 F. to 150 F. and that the pressure be in the range from 1 atmosphere to 1 atmospheres. The quantity of solvent used per volume of oil being treated will vary, depending upon the particular oil being treated, the solvent employed, as well as upon the yield and quality of the products desired. The volume generally will vary in the range from 0.2 to 6 volumes of solvent per volume of oil being treated. when treating oils boiling in the motor fuel boiling range and employing ortho and para toluene ethyl sulfonamides, it is preferred that to 3 volumes of solvent be used per volume of oil being treated.

In order to further illustrate the invention, the

The data indicate that the quality of extract produced by the toluene ethyl sulfonamide extraction is markedly better than that of either of the other two solvents. The raflinate quality of the sulfonamide compares favorably with that of the beta-phenoxy ethyl alcohol and exceeds that of the methyl carbitol. Since larger amounts of parafllnic material appear in the extracts from the solvents exhibiting lower selectivity, the higher total extract yields of the poorer solvents are to be expected. It should be noted that the higher extract yields of the carbitol and betaphenoxy alcohol should not be construed as refleeting unfavorably upon the sulfonamide. It also should be noted that the extraction with the sulfonamide was carried out at 80.F., whereas the other two extractions were conducted at 60 F. Since these three solvents behave in the customa 'y manner with respect to temperature, that is, the quality of extract decreases with increase in temperature, the degree of superiority of the sulfonamide is greater than indicated.

The process of the present invention is not to be limited by any theory or mode of operation, but only in and by the following claims in which it is desired to claim all novelty in so far as the prior art permits.

asaspio We claim:

1. Process for the segregation of a mineral oil into relatively more aromatic and into relatively more parafllnic constituents, comprising treating said mineral oil with a solvent selected from the class of alkyl aryl sulionamides under conditions to form a ramnate phase and a solvent extract phase, separating the respective phases and removing the solvent therefrom.

2. Process in acordance with claim 1 in which the alkyl group of said suli'onamide contains from one to tour carbon atoms in the molecule.

3. Process for the segregation of a mineral oil into relatively more aromatic and into relatively more paraillnio constituents, comprising treating said mineral oil with a solvent selected irom the class of toluene alkyl sulionamides under conitions to io'rm a raflinate phase and a solvent extract phase. separating the respective phases and removing the solvent therefrom.

4. Process in accordance with claim 3 in which said solvent is para toluene ethyl sulfonamide.

5. Process in accordance with claim 3 in which 1 said solvent is a mixture of ortho and para toluene ethyl suli'onamides.

5 6. Process for the segregation of petroleum oils boiling in the motor iuel boiling range into relatively more aromatic and into relatively more paramnic constituents, comprising treating said oil with a solvent selected from the class of alkyl aryl sulionamides.

7. Process in accordance with claim 6 in which said solvent is selected from the class oi toluene aikyl sulionamides.

8. Process in accordance with claim 6 in which said solvent comprises essentially a mixture of ortho and para toluene ethyl sulionarnides.

GEORGE W. GURD. WALTER'N. MUNB'I'ER. 

